Lens-grinding machine



L. e. SIMPSON.

I LENS GHINDING MACHINE. lAPPLICATION FILED NOV-30.11.918.

1,332,074. I l Peeented Feb. 24,1920.

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LEON G'. SIMPSON, OF. ROCHESTER, NEW YORK, ASSIGNOR TO BAUSCH AND LOMBOPTICAL COMPANY, 0F ROCHESTER, NEW' YORK, A CORPORATION OF NEW'v Yom;

LEN S-GRIN DING MACHINE.

Specication of Letters Patent.

Patented Feb. 24, 192,0.

Application led November 30, 1918. Serial No. 264,850.

To all whom t 'may concern Be it known that I, LEON G. SIMPSON, acitizen of the United States, residing at Rochester, in the county ofMonroe and State of New York, have invented certain new and usefulImprovements in Lens- Grinding Machines; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in vthe art to which. it appertainsto make and use the same.

My invention relates to lens grinding lmachines of the kind described inthe patent for lens grinding machines granted to me July 167 1918, andnumbered 1,272,546.` In said machine the lens carrier spindle is mountedin the end of an overhanging arm and rotated by gearing in the arm. Theobject of my present invention isto provide an improved gearing for thespindle which will operate freely without binding in all positions towhich the overhanging arm is movable. A further obj ect of my inventionis to provide a gearing on a revolving shaft which is movable relativelyto the axis of the shaft without alfectin its operation or drivingconnection with tglie parts driven thereby.

In the drawings:

Figure 1 is a side elevation of a lens grinding machine embodying oneform of my invention;

Fig. 2 is an enlarged horizontal section y.on

the line 2"- X of Fig. 1`;

Fig. 3 is a section on the line 3"---3x of Fig. 2.

Fig. 4 is a section on line 1x- 4* of Fig. 2; and

Fig. 5 isa diagrammatic viewl showing a mode of operation.

Similar reference characters refer to similar parts in all the views ofthe drawings.

A lens grinding machine embodylng my invention comprises a driven shaft1 rotatably mounted in a table or support 2 and having 'a lens grindingor polishing lap 3 secured thereto at its upper end. Coperating withsaid grinding lap is a lens carrier 4 to which a lens blank` is suitablyblocked by means of a suitable plastic material.

therefrom within the hollow post 8 is a shaft y 11.i having a sprocketwheel 12 keyed or otherwise secured thereto at its lower end. Avnoiseless chain connects the sprocket wheel 12 with a sprocket wheel 14keyed to the driven shaft 1.

The other end of the shaft 11 is provided with a spherical head or ball15 provided with a circumferential groove 16. Seated onthe head 15 andhaving a bearing thereon is a sprocket wheel 17 having the same numberof teeth as the wheel 10 to which it is connected by means of an endlesschain 18. The sprocket wheel 17 has a spherical recess or socket havinga bearing on the head 15 and a pair of diametrically oppositeprojections or pins 19 extend into the socket and into the groove 16 inthe head. The construction is such that the sprocket wheel is free toswing in all directions on the head 15 but through the pins or trunnions19 is constantly driven thereby.

In order to prevent the sprocket Wheel 17 from being displaced from thehead, the o ln side i's counter bored and receives a ring 20 also havinga spherical shaped socket adapted to have ,a bearing on the head. Toprevent binding of the sprocket wheel on the head due to unevenness ofthe parts, a bushing 21 may be inserted between a projecting part of thering and the opl osing part of the sprocket wheel. In or er to guide themovements of the sprocket Wheel with the movements of the overhangingarm, the latter is provided with a ring 22 which has a bearing against ashoulder 23 provided therefor on the sprocket wheel. By.l thisconstruction movemnt of the overhanging arm on the bracket 7 or lateralmovements of the arm to brin the lens carrier into cooperation with dierent parts of the grinding lap is transmitted to the sprocket wheel 17which is maintained in substantially the same plane with the sprocketwheel 10.

In order to take up the slack in the chain 18 and prevent rattling, Iprovide an adjustable idler 24 mounted on an arm 25 slidably adjustablein the overhanging arm to engage the idler with the chain. A set screw26 seated in a tapped opening in the overhanging arm engages the slideto secure it in adjusted position.

AS noted above, the sprocket wheels 17 and 10 have the same number ofteeth and are of substantially equal diameters. A s a result of thisconstruction the overhanging arm canY be movedfreely about the axis ofthe shaft 11 without binding, inasmuch as the same length of the chainis unwound from one sprocket and 'wound on the other. This feature ofthe operation is diagrammaticall illustrated 'in Fig.. 5 vof thedrawings. he construction yillustrated permits freedom of movement ofthe overhanging arm without binding of the driving connection betweenthe shafts l1 and 5 or changing the relative diametrical positionsthereof, such as might cause chattering and consequent inju to theworkpiece. 0

Having escribed my invention, what I claim and desire to secure byLetters Patent is:

1. In a lens grinding machine, the combination of a grinding lap, a lenscarrier spindle adapted to carry a lens blank in cooperative engagementtherewith, a sprocket wheel on said spindle, a driven shaft, a sprocketwheel on said shaft adapted to swing thereon but rotated with the shaft,and a chain operatively connecting said sprocket Wheels.

2. In a lens grinding machine, the combination of a grinding lap, a lenscarrier spindle adapted to carr a lens blank in coo erative engagement terewith, a s rocket wllieel on said spindle, a driven s aft, a sphericalhead on said shaft, a sprocket wheel seated on said head and free tomove thereon, means for rotatin .saidl sprocket wheel with the shaft,and a c am operatively connecting said sprocket wheels. v

3. In a lens grinding machine, the combination of 'a grinding lap, alens carrier spindle adapted to carry a lens blank in cooperativeengagement therewith, a sprocket wheel pn said spindle, a drivenl s Ispherical head on said shaft having a circumferential groove, a sprocketwheel seated on said head and having a free pivotal movementthereon,means coperating with said groove for turning the sprocket wheel withthe shaft, and a chain operatively connecting said sprocket wheels.

aft, a'

4. In a lens grinding machine, the combination of a grinding lap, a lenscarrier spindle adapted to carry a lens blank in cooperative engagementtherewith, a s rocket wheel on said spindle, a driven s aft, a sphericalhead on said shaft having a circumferential groove, a sprocket wheelseated on said head and having a free pivotal movement thereon, a pairof pins in said sprocket wheel projecting into said groove,forpreventing relative rotation between the sprocket wheel and shaft,and a chain operatively connecting said sprocket wheels.

5. In a lens grinding machine, the combination of a lens grinding lap, alens rinding spindle adapted to carry a lens lank in coperativeengagement therewith, a

sprocket wheel on said spindle, an overhanging arm in which said spindleis journaled, a rotatable post to which said overhanging arm is pivotedto swing in a vertical plane, sprocket wheel on said shaft` having afree swinging movement thereon but rotatable therewith, and a chainoperatively connecting said sprocket wheels.

6. In a lensA grinding machine, the c'oinbination of a lens grindinglap, a lens grinding spindle adapted to carry a lens blank in coperativeengagement therewith, a sprocket wheel on said spindle, an overhangingarm in which said spindle is journaled, a rotatable post to which saidoverhanging arm is pivoted to swing in a vertical plane, a revolubleshaft in said'post, a sprocket on said shaft having a free swingingmovement thereon but rotatable'therewith, means on said arm engagingsaid sprocket wheel to swing it with the movements of the arm, and achain operatively connecting said sprocket wheels.

7. In a lens grinding machine, nation of a grinding lap, a lens carrier.cooperating therewith, a spindle on which said lens carrier is mounted,a sprocket wheel on said spindle, an overhanging arm in which saidspindle is jcurnaled, a rotatable post to which said overhanging arm ispivoted to swing in a vertical plane, a driven shaft' in said post, asprocket wheel of substantially the same diameter as the first mentionedsprocket wheel mounted on said shaft for free Swingin movement thereonbut rotatable therewith, and an endless chain op eratively connectingsaid sprocket wheels, the construction being such that rotativemovements of the post will not affect the free operation of the chainwhen the overhanging arm is in either operative or inoperative position.v

8. In-a lens grinding machine, the combination of a grinding lap, a lenscarrier cooperatin lens carrier is mounted, a sprocket wheel on thecambi-- a revoluble shaft in said post, a

therewith, a spindle on which said said spindle, an overhanging arm inwhich free swinging movement thereon but rotasaid spindle is journaled,a rotatable post to table therewith, an endless chain operatively whichsaid overhanging arm is pivoted to connecting said sprocket wheels, andan ad- 10 swing in a. vertical plane, a driven shaft in justable idlerfor taking up the slack in said post, a sprocket wheel of substantiallysaid chain.

the same diameter as the vrst mentioned v sprocket wheel mounted on saidshaft -for LEON G. SIMPSON.

